Yukon V8-350 5.7L (1992)
Ignition Control Module: Description and Operation
PURPOSE
The distributor reference signal provides the control module with both engine RPM and crankshaft position information. This enables the control
module to operate the fuel pump relay and energize the fuel injector.
OPERATION
When the engine is cranking or running the control module receives Distributor Ignition (DI) reference pulses from the ignition module. If the wire
becomes open or grounded the engine will not run, as the control module will not operate the injector.